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Patented Jan. 2, 1923.

UNITED STATES PATENT QFFICE.

EDOUARD PAUL SISLEY, OF LYON, FRANCE, ASSIGNOR T9 SOCIETE CHIMIQUE DESUSINES DU REZONE, 9F PARIS, FRANCE.

PROCESS FOR DYEING- C ELLULOSE ACETATE.

N 0 Drawing.

To all whom it may concern:

Be it known that T, Eoouann PAUL Sis- LEY, residing at Lyon, France, acitizen of the Republic of France, have invented certain new and usefulImprovements in Processes for Dyeing Cellulose Acetate.

Acetate of cellulose not being permea le to water it is difficult to dyethreads, iilms or other articles made with this material bythe usualprocesses as the dyeings ol tained are light and badly united.

I have discovered that articles made with cellulose acetate can beadapted. to he dyed by treating them in a bath of triphosphate ofsodium.

Example.

The cellulose acetate artificial silk is slowly agitated for a hour toone hour in a bath containing per litre 525 grammes of crystallizedphosphate (dibasic) of sodium, and 5 0. cm. of caustic soda solution 36Baum. The bath is maintained between and 70 C. during the whole durationof the operation.

The silk is then thoroughly washed and dried, the loss of weight being 6per cent.

The process can be applied to pure cellulose acetate fabrics or to mixedfabrics such as cellulose actate silk and natural silk, or celluloseacetate silk and wool.

The process which is the object of this invention may be combined withthe dyeing itself so that the whole operation takes place in a singlebath.

The cellulose acetate treated with tribasic phosphate can also bemordanted with tannin and tartar emetic (double tartrate of antimony andpotassium) before being placed into the dyeing bath.

What I claim and desire to secure by Letters Patent is 1. A process forpreparing cellulose: acetate for dyeing consisting in treating thecellulose acetate articles with a tribasic phosphate of sodium solution.

2. A process for preparing cellulose acetate for dyeing, consisting intreating cellulose acetate articles with a solution of tribasicphosphate of sodium produced in the bath itself.

Application filed September 20, 1921. Serial No. 502,047.

3. A process for preparing cellulose ace tate for dyeing, consisting intreating the cellulose acetate articles with a solution of tri-basicphosphate of sodium produced in the bath itself by the reaction or"crystallized di-basic phosphate of sodium on caustic soda.

4. A process for preparing cellulose acetate for dyeing, consisting intreating the cellulose acetate articles in a bath containing per litre525 grammes of crystallized dibasic phosphate of sodium and 5 c. cm. 0;?caustic soda solution 36 Baum.

5. A process for preparing cellulose acctate for dyeing consisting intreating the cellulose acetate articles in a bath containing per litre25 grammes of crystallized (dibasic) phosphate of sodium and 5 0. cm. ofcaustic soda solution 36 Baum the bath being maintained at a temperatureof 60 to 70 C. during the treatment.

6. A process for preparing; cellulose acetate for dyeing, consisting inslowly agitatin the cellulose acetate articles for to one hour in a bathcontaining per litre 25 grammes of crystallized (dibasic) phosphate ofsodium and 5 0. cm. of caustic soda solution 36 Baum, the bath beingmaintained at a temperature 01" 60 to 70 C. during the treatment.

7. The process of dyeing cellulose acetate articles, which consists intreating the articles with a tribasic phosphate of sodium solution towhich the dye has been added.

8. The process for preparing cellulose acetate for dyeing which consistsin treating cellulose acetate articles with a solution of sodiumphosphate.

9. The process for preparing cellulose'acetate for dyeing which consistsin treating cellulose acetate articles with a solution of sodiumphosphate in the presence of caustic soda.

10. The process of dyeingcellulose acetate articles which consists intreating the said articles with a solution of sodium phosphate andcaustic soda to which a dye has been added.

In testimony whereof I have signed my name to this specification.

EDOUARD PAUL SISLEY.

